Forthcoming Events

05.09.2022 - 09.09.2022, Iseolago hotel, Iseo, Italy.

News

MUST2022 Conference- a great success!
New scientific highlights- by MUST PIs Wörner, Chergui, and Richardson
FELs of Europe prize for Jeremy Rouxel- “Development or innovative use of advanced instrumentation in the field of FELs”
Ruth Signorell wins Doron prizefor pioneering contributions to the field of fundamental aerosol science
New FAST-Fellow Uwe Thumm at ETH- lectures on Topics in Femto- and Attosecond Science
International Day of Women and Girls in Science- SSPh asked female scientists about their experiences
New scientific highlight- by MUST PIs Milne, Standfuss and Schertler
EU XFEL Young Scientist Award for Camila Bacellar,beamline scientist and group leader of the Alvra endstation at SwissFEL
Prizes for Giulia Mancini and Rebeca Gomez CastilloICO/IUPAP Young Scientist Prize in Optics & Ernst Haber 2021
Nobel Prize in Chemistry awarded to RESOLV Member Benjamin List- for the development of asymmetric organocatalysis
NCCR MUST at Scientifica 2021- Lightning, organic solar cells, and virtual molecules
#NCCRWomen- NCCR MUST celebrates 50 years women’s right to vote in Switzerland

Impact of strong picosecond THz pulses on dielectrics and semiconductors

Date Fr, 12.07.2019 - Fr, 12.07.2019
Time 14:00h
Speaker Prof. Elena Mishina, MIREA – Russian Technological University - Moscow, Russia
Location ETH Hönggerberg, HPF G-6
Program Direct manipulation of the atomic lattice using high power single-period THz pulses allows to create new states of matter in complex materials. This is possible due to strong anharmonicity of ionic potential due to excitation by strong transient electric field of THz pulse, which ranges up to tens of MV/cm. This pulse can dynamically alter the lattice structure and provide through phonon-phonon coupling coherent control over specific phonons including soft modes. Two types of unharmonic processes were reported so far. The first one is to resonantly excite high frequency vibrational mode and to modify the lattice structure through indirect coupling of this infrared-active phonon to other, lower frequency lattice modulations. The second one is opposite: to drive the lowest frequency optical phonon in the into the anharmonic regime with a strong terahertz pulse and transfer energy to higher frequency phonon modes through nonlinear coupling. In semiconductors, high electric fields produces electrical breakdown due to avalanche of electrons generated by impact ionization. This effect has been studied for decades in electronic devices in CW or low frequency field. Ultrashort THz pulse gives birth to absolutely new effects, when impact ionization takes place but it does not lead to breakdown because of high localization in time and space.
Download (75 KB)
(75 KB)
Link Laser Seminars
NCCR MUST Office : ETHZ IQE/ULP-HPT H3 | Auguste-Piccard-Hof 1 | 8093 Zurich | E-Mail
The National Centres of Competence in Research (NCCR) are a research instrument of the Swiss National Science Foundation